Kwon-Chung K J, Tom W K, Costa J L
J Clin Microbiol. 1983 Dec;18(6):1419-21. doi: 10.1128/jcm.18.6.1419-1421.1983.
Several indoles served as substrates for the phenoloxidase of Cryptococcus neoformans and resulted in the production of a melanin-like pigment. In general, a higher percentage of C. neoformans var. neoformans (A and D serotypes) isolates could produce pigment from indoles than could those of var. gattii (B and C serotypes). Only compounds with a hydroxyl or an amino group on the phenyl ring produced pigment; methoxy, nitro, methyl, and fluorine substituents on the phenyl ring were inactive, as was a hydroxyl group at the 2 position on the indole ring. The phenoloxidase of C. neoformans thus appears to differ from that found in Mycobacterium leprae, which cannot use a hydroxyindole, desoxyfructo-5-hydroxytryptamine, as a substrate. In addition, C. neoformans differs from M. leprae in that desoxyfructo-5-hydroxytryptamine does not inhibit the uptake of dihydroxyphenylalanine into the cell.
几种吲哚可作为新型隐球菌酚氧化酶的底物，并导致产生一种类似黑色素的色素。一般来说，新型隐球菌变种新型隐球菌（A和D血清型）分离株从吲哚产生色素的比例高于加蒂变种（B和C血清型）。只有苯环上带有羟基或氨基的化合物才能产生色素；苯环上的甲氧基、硝基、甲基和氟取代基无活性，吲哚环上2位的羟基也无活性。因此，新型隐球菌的酚氧化酶似乎与麻风分枝杆菌中的不同，麻风分枝杆菌不能将羟基吲哚、脱氧果糖-5-羟色胺用作底物。此外，新型隐球菌与麻风分枝杆菌的不同之处在于，脱氧果糖-5-羟色胺不会抑制二羟基苯丙氨酸进入细胞。
